WO 03101525 A1 discloses a suppository applicator consisting of a piston arranged to be displaced within a tubular sleeve in a suppository applicator when an end piece of the piston is provided with a force being opposed by means of an equally large and oppositely directed counter-force being applied to a finger grip. The piston and the tubular sleeve are attached to each other by means of two elastic and resilient elements placed on the outside of said piston. When force applied to the end piece of the piston ceases, the piston returns to the position that the piston held before applying the force.
FR 2610831 A1 discloses a syringe for inserting suppositories, whatever the size, in a hygienic manner, and also to prevent the suppository from melting during handling, in particular in hot countries. It consists of a cylindrical plastic tube, into which a pusher is inserted, provided with a rod which is used for guiding the suppository trapped by three clamps fixed to the end of the tube. The apparatus is in particular intended for hospitals, clinics and individuals, in particular large persons for whom fitting suppositories presents the greatest difficulty.
DE 3031408 A1 discloses an inserting device, in particular for suppositories, characterized in that the device comprises a sleeve-shaped housing, wherein the piston is movingly guided, having an actuating element at one end and the operating element at the opposite end of the housing, wherein a portion of the inner housing wall has a cup-like receiving area for a suppository and wherein the length of said receiving area is variable by the piston displacement.
U.S. Pat. No. 5,860,946, the disclosure of which is incorporated herein by reference, describes an instrument for inserting a suppository, comprising a tube with a first end which is adapted for receiving a suppository and a second end through which a plunger is inserted in the tube. The first end defines the front or distal end of the instrument in the direction of insertion, and the second end defines the rear or proximal end. The plunger has corresponding first and second ends, the first end having a circular cross section and two axially spaced circumferential flanges and the second end adapted to project from the second end of the tube before manual actuation of the instrument by the user to eject the suppository from the first end of the tube. The first end of the tube has an inwardly extending shoulder which engages between said flanges of the plunger, this engagement having the purpose of holding the plunger in the tube, with the second end projecting form the tube as described above, before the suppository is ejected. The first end of the plunger is divided in to a number of sectors by radial slots.
Prior to ejection, the suppository is held in the first end of the tube of the prior art device by opposite resilient tongues having, in walls facing each other, recesses mating the outer contour of the suppository.
The user manually actuates the instrument by pushing the projecting second end of the plunger fully into the tube, which causes the plunger to disengage from its position held by the shoulder and the flanges and move forwards in the tube to push the suppository out of the front end of the tube.
Experience has shown that the prior art device has a number of disadvantages. For example, the suppository can become damaged by scraping against the tongue walls of the tube in the ejection process. Another disadvantage is that the user has no way to know with relative certainty that the suppository has been ejected correctly—for example in the vicinity of the cervix as far as an intravaginal applicator is concerned. The holding cooperation between the shoulder and the flanges, which provides the pre-actuation holding of the plunger, is weak and the plunger can quite easily be prematurely pushed forwards in the tube to eject the suppository. After actuation the plunger can freely move forwards and backwards in the tube and can even be returned to the held condition.
The present instrument aims to at least partially overcome these problems or at least to provide an alternative instrument for inserting a suppository.